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The term “Passive Solar Energy” means that basic physical concepts (such as sunshine, warm air rising, and cool air falling) are used to HEAT and COOL a building, WITHOUT the need for fans, water pumps, or other “active” mechanical equipment. Using solar radiation to Passively Heat Air and Water is VERY EASY AND INEXPENSIVE TO DO.

Using the sun's solar energy for Cooling and Dehumidification in a hot humid climate, (where the nighttime air is too warm and contains too much water vapor to use for direct ventilation), is a challenging engineering problem that Zero Energy DesignTM, Inc. solved cost effectively in 1979, without the use of expensive conventional compressor-based air conditioning equipment.

When nighttime air is TOO WARM (above 80 degrees F) and it contains TOO MUCH WATER VAPOR (above 50% Relative Humidity) then it should NOT be used for direct building ventilation. We must have some method of cooling the air and removing water vapor from it. Our achievable, proven Zero Energy Design goal is to eliminate net energy bills by doing precisely that. VERY FEW people (other than those trained by Zero Energy DesignTM) understand the practical state-of-the-art design-and-implementation issues of Passive Solar Energy Cooling in a Hot, Humid Climate.

We are committed Passive Solar Energy Research Scientists with a long track record of consistent success. We provide three decades of experience, extensive comprehensive solution specifics, and many details that are simply NOT available for any other source. Our materials are internationally copyrighted, but we have chosen to NOT patten our proven designs, for the betterment of humanity.

Some Passive Solar Energy techniques were understood by ancient Greeks 2500 years ago, like orienting entire communities with tens of thousands of buildings so that every one takes advantage of winter sunshine, while blocking the hot summer sun (when it is 47 degrees higher than the low winter sun). Some modern Passive Solar Energy techniques are very-new “state of the art” that do not yet appear in any other text book. For 30 years (since Jimmy Carter’s 1978 Solar Energy Tax Credits) Natural Energy Applied Research, and Zero Energy Design, inc., have been demonstrating state-of-the-art Passive Solar Energy technology that can eliminate conventional heating and cooling bills. Our ZED book has been growing, and iteratively refined for nearly THREE DECADES. Our ZED CD-ROM is the most comprehensive and complete information resource on Passive Solar Energy Heating and especially Passive Solar Energy Cooling that we have ever heard of anywhere. We hold nothing back - It answers most of the questions we have been asked over three decades.

Today, we design Zero Energy Buildings that can have NO ENERGY BILLS. They do not even have to be connected to any energy company. After construction, they produce NO GREENHOUSE GASES, and do NOT contribute to man-made climate change Global Warming, or pollution of our delicate environment. Our buildings can help eliminate the need to ever build any more fossil fuel or nuclear power plants.

6-minute "Abundant Energy Brilliant Future"
Narrated Introductory
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Introductory Passive Solar Energy Technology Overview

Passive Solar Energy Concepts can be added to any existing building (obviously for additional cost). BUT, Passive Solar Energy Technology is the LEAST EXPENSIVE (and the most effective) when it is holistically integrated into the exterior envelope of a NEW building. Passive Solar Energy new construction can actually COST LESS per square foot than traditional construction, since Passive Solar Energy Design, plus Holistic Systems Engineering, can REDUCE (or eliminate) the need for expensive-to-install-and-operate conventional heating and cooling systems.

Seasonal
and Hourly Sun Path

If we are going to use the clean, FREE, renewable energy from the sun, we must know where it is going to be.

Earth's rotation tilts about 23.5 degrees on its pole-to-pole axis, relative to the plane of Earth's solar system orbit around our sun. As the Earth orbits the sun, this creates the 47-degree peak solar altitude angle difference, and the hemisphere-specific difference between summer and winter.

In the Northern hemisphere, the winter sun rises in the southeast, peaks out at a low angle above the southern horizon, and then sets in the southwest. It is on the south (equator) side of the house all day long. Vertical south-facing (equator side) glass is excellent for capturing solar thermal energy.

This is not true in the summer, when in the northern hemisphere, the sun rises in the northeast, peaks out nearly straight overhead (depending on latitude), and then sets in the northwest. A simple latitude-dependant equator-side overhang can easily be designed to block 100% of the direct solar gain from entering vertical south-facing windows on the hottest days of the year. Roll-down exterior shade screens, interior translucent-or-opaque window quilts, drapes, shutters, movable trellises, etc. can be used for hourly, daily or seasonal sun and heat transfer control (without any active electrical air conditioning).

The latitude (and hemisphere)-specific solar path differences are critical to effective passive solar building design. They are essential data for optimal window and overhang seasonal design. Solar designers must know the precise solar path angles for each location they design for, and how they compare to place-based seasonal heating and cooling requirements.

In the U.S., the precise location-specific altitude-and-azimuth seasonal solar path numbers are available from NOAA - The "equator side" of a building is south in the Northern hemisphere, and north in the Southern hemisphere, where the peak summer solstice solar altitude occurs on december 21st. The sun rises in the east and sets in the west everywhere on Earth.

On the Equator, the sun will be straight overhead and a vertical stick will cast no shadow at noon (solar time) on March 21 and September 21, the equinox. 23.5 degrees north of the equator on the Tropic of Cancer, a vertical stick will cast no shadow on June 21, the summer solstice. The rest of the year, the noon shadow will point to the North pole. 23.5 degrees south of the equator on the Tropic of Capricorn, a vertical stick will cast no shadow on December 21, the summer solstice, and the rest of the year its noon shadow will point to the South pole. North of the Tropic of Cancer, the noon shadow will always point north, and conversely, south of the Tropic of Capricorn, the noon shadow will always point south. North of the Arctic circle, and south of the Antarctic circle there will be at least one day a year when the sun is not above the horizon for 24 hours, and at least one day (six months later) when the sun is above the horizon for 24-hours.

In the moderate latitudes (between the circles and tropics, where most humans live), the length of the day, solar altitude and azimuth vary from one day to the next, and from season to season. The difference between the length of a long summer day, versus a short winter day increases as you move farther away from the equator.

All passive solar building designers must know this absolutely-critical environmental information precisely for their specific location. It has to be included in 3D seasonal solar-design mathematical computer simulation models, used by modern passive solar building designers.

When designing active solar panels, it is also important to be familiar with the latitude-specific seasonal hourly path of the sun.

Passive Solar Energy Heating Of Interior Air in a cold climate (with typical U.S. levels of sunshine) is extremely EASY and inexpensive to implement. Passive Solar Energy Heating begins with VERTICAL EQUATOR-SIDE (SOUTH-FACING) GLASS (or north-facing glass in the southern hemisphere). The winter sun is quite low (often less than 30 degrees above the horizon) in the winter. Direct sunlight easily penetrates vertical glass and can heat a room well above 80 degrees F, when it is below freezing outside.

When there is snow on the ground, the reflection of the low winter sun off of the snow significantly increases the Passive Solar Energy Heating effect, with reflected sunlight on your interior ceiling.

In the summer, the noonday sun is 47 degrees higher than in the winter. Place-based, location-specific overhangs are designed above the equator-side windows, so that NO DIRECT SUNLIGHT CAN ENTER THE GLASS IN THE SUMMER, when the sun rises in the northeast, is nearly straight overhead at noon, and then sets in the northwest. Understanding the PRECISE seasonal path of the sun in your location is critical to effective PASSIVE SOLAR ENERGY HEATING, and PASSIVE SOLAR ENERGY COOLING, especially in hot humid climates.

Roof-angled glass should ALWAYS BE AVOIDED IN ALL LOCATIONS. Roof-angled glass (and most skylights) are a SOLAR FURNACE when the summer sun is nearly straight over head. Most of low winter sunlight reflects off of roof angled glass (due to the nearly-parallel “angle of incidence”).

In the winter, warm air rises and the hottest air in the room touches your ceiling glass. This creates high heat transfer (large energy bills), due to the large temperature differential across the ceiling glass, which has low resistance to heat flow. Roof-angled glass is like a THERMAL HOLE in your ceiling / roof.

If you ever see any building with roof-angled glass, or skylights, then you can be certain that its designer did NOT have the first clue about the ancient engineering principles of Passive Solar Energy Design. The Romans who invented glass over two thousand years ago quickly discovered that roof-angled was very bad thermally: summer AND winter. Roof glass also often leaks water, and can break in a hail-or-wind storm. If you currently have roof-angled glass in your home, it should be removed and the hole weather sealed and well insulated.

Passive Solarium Design Issues

In a new-construction Zero Energy DesignTM - Passive Solar Energy Home, we generally design in a Solarium (Greenhouse) with a lot of protected vertical glass on the equator side of the thermal envelope. It is important that it be ISOLATED from the interior (sleeping quarters) of the home. The Solarium then acts as a THERMAL BUFFER ZONE – at moderate temperatures that are typically between interior and exterior temperature extremes. There is then a lot of INTERIOR glass that divides the Solarium / Greenhouse space from the interior of your home. Instead of having only one wall between your interior and outside temperature extremes, you have TWO layers of glass. The engineering principle is that TWO SMALL TEMPERATURE DIFFERENTIALS PRODUCE MUCH LOWER HEAT TRANSFER THAN ONE LARGE TEMPERATURE DIFFERENTIAL

The amount of south-facing solar heating glass is determined by the local solar gain potential, and the degree-day heating requirement in the winter. It is even needed in the northern half of tropical Florida, where the winter temperature sometimes drops below freezing when the frigid Canadian jet stream swings south.

In the past, passive solar designers have often used too much glass and been surprised at the need to exhaust excess heat on very cold clear winter days. We have also observed that winter solar gain increases due to reflection from the low angle of the sun through vertical south-facing glass, when snow is on the ground. This is a desirable winter heating characteristic of passive solar design that architects need to understand when sizing solar glass in snowy climates.

During winter days, the Solarium is heated nicely from CLEAN, FREE, Abundantly-Available, Passive Solar Radiation. We design in Natural Convection Air Flow Paths so that south-side solar gain is transferred to the colder rooms on the north side of your house, without the need for fans, thermostats, or electricity.

The amount of south-facing solar heating glass is determined by the local solar gain potential, and the degree-day heating requirement in the winter. It is even needed in the northern half of tropical Florida, where the winter temperature sometimes drops below freezing when the frigid Canadian jet stream swings south.

In the past, passive solar designers have often used too much glass and been surprised at the need to exhaust excess heat on very cold clear winter days. We have also observed that winter solar gain increases due to reflection from the low angle of the sun through vertical south-facing glass, when snow is on the ground. This is a desirable winter heating characteristic of passive solar design that architects need to understand when sizing solar glass in snowy climates.

Excess daytime solar heat is stored in THERMAL MASS that is engineered into your Passive Solar Home. It prevents your home from getting too warm on sunny winter days, and it heats your entire home on cold winter nights. When the air outside gets extremely cold in the winter, the moisture precipitates out (as snow, etc.). This leaves clear skies, excellent solar gain, which is enhanced by reflection off of the snow that lights up the CEILING of your Solarium. How wonderful!

The Zero Energy DesignTM Thermal Buffer Zone experiences small temperature swings that are much less than the outside temperature, and the interior of your home remains a fairly stable temperature and humidity, without the harsh drying effect of a conventional expensive heating system. The interior of your home “thinks” it was built in a tropical environment where it can get 88 degrees F (with snow on the ground on sunny days) and only the low 60’s at night (in most U.S. locations). Sunbathing in the warmth of the Solarium on a cold winter day is exhilarating. Your skin gets nice and warm, but you cannot get a sunburn through the south-facing glass, which blocks most harmful ultraviolet rays.

The Sunroom / Solarium / Greenhouse is a great place for a year-round solar-heated swimming pool, swim spa, or hot tub. Our first Zero Energy DesignTM Passive Solar Home in 1979 had a 38-foot indoor swimming pool. We swam in 90 degree F solar heated water, with 10 degree snow outside. Almost everyone who toured our innovative 1979 home were more impressed with its unique beauty, than with the fact that we did it with no heating or cooling bills. We have learned much more since then.

In moderately cold U.S. climates, we often use a lot of south-facing glass (up to ceiling-to-floor, wall-to-wall in some locations). There is then sweeping INTERIOR glass that divides the Solarium / Greenhouse space from the interior of your home, and creates panoramic southern views in most room of the house. Our house plans are NOT conventional with indiscriminate use of glass on all sides of the envelope.

Instead of having only one wall between your interior and the summer / winter outside temperature extremes, our Passive Solar Energy Homes have TWO layers of glass. The engineering principle is that TWO SMALL TEMPERATURE DIFFERENTIALS PRODUCE MUCH LOWER HEAT TRANSFER THAN ONE LARGE TEMPERATURE DIFFERENTIAL as in the case of a traditional building with no Thermal Buffer Zone on any side.

During winter days, our equator-side sunrooms are heated nicely from CLEAN, FREE, Abundantly-Available, Passive Solar Energy Radiation. We design in “Natural Convection Air Flow Paths” so the south-side warm air is transferred to the colder rooms on the north side of your house, WITHOUT the need for fans, thermostats, or electricity. The sunnier that it is outside, and the colder the north side, the higher the north-to-south pressure differential will be, and the faster our self-regulating convection air flow becomes.

Excess daytime Passive Solar Energy is stored in THERMAL MASS that is engineered into your Passive Solar Energy Home. The Thermal Mass prevents your home from getting too warm on sunny winter days, and it heats your entire home on cold winter nights – allowing only very gradual temperature changes from day to night, and from one season to the next.

When the air outside gets extremely cold in the winter, the water vapor in it precipitates out (as snow, etc.). This leaves clear skies and excellent solar gain, which can be greatly enhanced by reflection off of the snow - Which lights up the CEILING of your Solarium. How wonderful! Extreme cold, implies high Passive Solar Energy Heating potential, in most locations with north and south latitudes that are similar to those of the continental United States.

Our Zero Energy DesignTM Thermal Buffer Zone experiences small temperature swings that are much less than the outside temperature, and the interior of your home remains a fairly stable temperature and humidity, without the harsh drying effect of a conventional expensive heating system. The interior of your Passive Solar Energy home “thinks” it was built in a tropical environment, where the solarium can get 88 degrees F (with snow on the ground on sunny days) and only the low 60’s at night (in most U.S. locations). Sunbathing in the warmth of the equator-side Solarium on a cold winter day is exhilarating. Your skin gets nice and warm, but you can NOT get a sunburn through the south-facing glass, which blocks most of the sun’s harmful ultraviolet rays.

Your Sunroom / Solarium / Greenhouse is a great place for a year-round solar-heated swimming pool, swim spa, or hot tub. Our first Zero Energy DesignTM Passive Solar Energy Home in 1979 had a 38-foot indoor swimming pool. We swam in 90 degree F solar heated water, with 10 degree snow outside. Almost everyone who toured our innovative 1979 home were more impressed with its unique beauty, than with the fact that we designed it to have no conventional heating or cooling bills. We have learned much more since then. Our new-millennium Passive Solar Energy buildings are even better than our significant Zero Energy DesignTM successes three decades ago.

There are a thousand mistakes that conventional architects and builders may design into your home, which greatly increase your need to pay escalating utility bills. For example, every time you turn on your clothes dryer, you waste a lot of expensive energy, AND you suck a large volume of conditioned air out of your home, which is replaced with dirty, unconditioned air that you have to pay escalating energy bills to make the correct temperature and humidity. How stupid is that? BUT, almost all business-as-usual architects design many similar serious flaw into today’s energy-inefficient homes. We have a far-superior, convenient way to design an interior laundry room that eliminates this needless waste of expensive air-conditioning energy.

70% to 90% of why Zero Energy DesignTM Passive Solar Energy Technology works so very well, is SUPERIOR ENERGY EFFICIENCY designed into the entire building with our unique approach to Holistic Systems Engineering. We avoid the Common Careless Construction Bad Thermal Things, so that minimal Passive Solar Energy Technology can eliminate your heating and cooling energy requirements altogether. Our CD-ROM provides all of the specific details for over 1,000 specific solutions. It is hundreds of megabytes of material, which would be too large to publish entirely online. Our CD-ROM even includes some brief movies of some of our recent Zero Energy DesignTM projects.

Passive Solar Energy Water Heating is another easy-to-implement concept in most of the U.S. (where solar energy is plentiful much of the time). If you simply lay a dark garden hose out in the sun, the water in it will get fairly warm. It will not boil, but it can get as hot as what is in your conventional hot water tank.

Throughout most of the U.S., the AVERAGE ANNUAL solar gain potential is significant, ranging from over 1,000 BTU/sq.ft./day to over 1,800 BTU’s. On cloudy winter days, solar gain potential is well below average (sometimes only 30%). In the summer, solar gain potential is often over 3,000 BTU/sq.ft./day in many areas. Solar hot water is feasible and cost-effective most of the year in most locations, using all but the lowest capacity “cheap” solar water heating systems.

Flat Solar Water-Heating panels are easy to construct, with price competition between manufactures. They are black with a large area designed to maximize solar radiation absorption. It is important that they be oriented correctly, to maximize their economic benefit on a total annual basis. Different manufacturers models are compared at the Florida Solar Energy Center's "Solar Thermal Collectors, Hot Water Ratings".

There are multiple types of Zero Energy Home solar hot water systems. The simplest is a cheap “passive” solar hot water heater (called a “thermosiphon” - used in southern U.S. tropical areas that seldom freeze).

A Passive Solar Energy Thermosiphon can be inexpensively constructed, that needs no pumps, thermostats or electricity to operate effectively, and it significantly reduces your water heating bills. It consists of Solar Water Heating Panel(s) that must be LOWER than an Insulated Hot Water Storage Tank.

A passive solar thermosiphon hot water heater is basically a solar collector (made up of black water tubes designed to absorb solar radiant energy), connected to an insulated hot water storage tank, which must be higher than the collector.

When the sun shines on the solar collector, the warmer water expands somewhat and becomes lighter than colder water in the storage tank. “Natural Convection” causes the warmer water to rise into the tank (like warm air rises up a chimney), and the coldest water to descend into the collector, where it is warmed and circulates back into storage in a continuous gravity-fed “flow loop” that gradually warms the stored water, depending on the available BTU’s/sq.ft. of solar gain potential, and solar collector square footage. The system is engineered to economically meet the large-or-small desired hot water needs of the owner.

When you use hot water, it is drawn from the hottest part of the Passive Solar Energy Hot Water Storage Tank, and then it flows through an efficient conventional hot water tank, which can be located anywhere in your home. If you use less hot water than you capture with the sun, the conventional tank never needs to come on – its thermostat always sense hot water. If you run a lot of hot water at night, then you will use some conventional energy, but not nearly as much as if you did not have a way to heat part of your water with the sun.

Passive Solar Energy Cooling In A Hot Humid Climate

"Passive Solar Cooling"

Many Johnny-Come-Lately experimenters FALSELY claim to have Passive Solar Cooling, by merely using sunlight to heat air at the top of a building, which then creates a vacuum that draws in outside air at the base of the building. This trivial concept is Passive Solar Ventilation, but it is NOT a workable COOLING or DEHUMIDIFICATION solution in a hot humid location, where the summer nighttime temperature rarely drops much below 80 degrees F, and the nighttime relative humidity is always ABOVE the maximum 50% healthy comfort zone (as in most of Florida, where conventional 24-hour-a-day air conditioning bills are quite high).

Relative Humidity above 50% encourages ugly mold growth (some of which is known to be DEADLY). Hot, humid, exterior ventilation can be EXTREMELY UNHEALTHY - Especially for people who are allergic to mold, pollen, outside pollution, dust and dust mites (the most significant asthma trigger).

Hot humid climates REQUIRE the temperature AND humidity to be significantly lowered by some means, 24-hours a day for most of the summer (and beyond). The summer air conditioning bills for many America homes are the highest energy expense that they have all year long. The obvious for cost-effective Passive Solar Energy Cooling is obviously significant, and VERY FEW people have even a clue how to make it happen WITHOUT expensive conventional compressor-based air-conditioning systems.

Power companies generally experience their peak annual electricity loads on summer afternoons. When multiple nearby locations have electrical peaks at the same time, our century-old obsolete power grid design frequently shuts down (sometimes-deadly electrical blackouts and brownouts).

By using Zero Energy DesignTM Advanced Passive Solar Energy Cooling Technology, peak loads can be greatly reduced, which will dramatically reduce the need to build new dirty highly-polluting electric power generation systems, improve our environment and human health worldwide. The cost / benefits of increased use of well-documented Passive Solar Energy Cooling Technology are enormous, in many different ways, for individuals, companies, countries, AND for the entire Earth’s delicate climatic environment.

Zero Energy DesignTM has documented and demonstrated dozens of practical cost-effective solutions that both lower temperature AND humidity, WITHOUT the high operating cost of a conventional compressor-based air-conditioning system. Passive Solar Energy can actually REDUCE the cost per sq.ft. of a new Zero Energy DesignTM Building. Some of our cooling concepts are ancient, and some are new, UNIQUE, state-of-the-art approaches, which are understood by very few people (other than those we have trained in Zero Energy Design). The following is a small high-level summary of a few – the significant specific details are in our DOE Workshop, and on our bargain $25 ZED CD-ROM.

Perhaps one of the largest summer cooling mistakes made by business-as-usual non-caring architects and builders is designing and constructing a “Hot Box Attic.” If the temperature in YOUR attic ever gets HOTTER than the peak outside air temperature, IT IS EXTREMELY POORLY DESIGNED. This very-bad thermal design practice has become so common in recent energy-inefficient construction that most homebuyers think nothing of it, and incorrectly assume that all attics must get hot in the summer. We have proved how very false this is. In the summer, your roof should act like a shading device, NOT like a conventional Solar Furnace Hot Box Attic!

A hot attic means a hot ceiling, even if you have more than a foot of fiberglass insulation. Fiberglas is (as its name clearly states) merely spun GLASS fiber. You know that solar radiation passes right through glass windows. Radiant heat energy also easily passes through fiberGLASS insulation.

Your roof gets hot in the summer sun. Radiation from the bottom of your roof decking RADIATES INFRARED HEAT DOWNWARD, where it easily passes through fiberglass insulation, making the bottom of your ceiling hot, and increasing your air conditioning bills. If you have a ceiling fan running when no one is in the room, it creates air turbulence (the opposite of wind chill), which accelerates downward heat transfer from your Hot Box Attic into your air-conditioned rooms.

Basically, the upper rooms of your house “think” they were built in a climate that gets over 150 degrees F, AND you must consequently pay high cooling bills. Spectacularly stupid right?

Almost all architects and builders are clueless about the mechanisms of heat transfer: Conduction, Convection, and especially Radiation, which is the MOST significant one, especially in downward heat flow in the summer. They are NOT Energy Research Scientists, as we are.

The only thing dumber than a Hot Box Attic, is putting air-conditioning ducts-or-equipment in your Hot Box Attic (or unconditioned crawlspace or garage). The High Temperature Differential, and any installation flaws or leaks from aging, greatly reduce the thermal performance of your system – making it run much longer, and uselessly wasting sometimes more-than-half of what you pay for air conditioning energy. We discuss many specific energy-efficient construction details on our CD-ROM.

For THREE DECADES, Energy Research Scientists at Zero Energy DesignTM have been PROVING how it is easy to design an attic that NEVER gets as hot as the peak outside air temperature. We use cool roofing, interior radiant barriers, and ventilation with replacement air that is COOLER AND DRIER than outside summer air. Our ZED Cool Attic Thermal Buffer Zone can reduce the air conditioning load on the upper rooms of your house by 60 degrees F!

Our Holistic Systems Engineered roof acts like shading, instead of a traditional attic-space solar furnace. The upper rooms of your new ZED house will “think” they were built in a moderate climate, where the sun never shines in the summer – Very EASY to keep cool, with relative humidity below 50%.

In a similar fashion, we have hundreds of detailed specifics that lower (or eliminate) your need for an expensive compressor-based air conditioning system. They can both (1) REDUCE the initial purchase price of a Zero Energy Home, and (2) REDUCE OR ELIMINATE monthly energy bills – Forever.

Absorption Chiller Technology

Consider the following: How was ice made commercially 130 years ago BEFORE the electric light bulb was invented? It was called “absorption chilling.” It used NO electricity, no motors or pumps to make large blocks of ice for use in old-fashion pre-electric “ice boxes.” Horse-draw wagons delivered the ice to consumers.

Well-known absorption chiller technology uses a heat source to warm one end of a recirculating “phase change” system. The other end gets cold enough to freeze large quantities of ice – No electricity or motors required. They are used in many recreational vehicle “propane refrigerators” today, which do NOT need electricity to keep your food cold. It sounds counterintuitive – that heat can be used to make ice, but it is STILL a very cost-effective system 130 years later.

Since passive absorption chillers have no moving parts (other than the fluid), they almost never wear out (the way conventional compressor-based air-conditioners do every few years today). Century-old absorption chiller antiques still work today. They were replaced with compressor-based refrigerators in the early 1900’s, by manufacturers who wanted to constantly sell replacement equipment that was intentionally DESIGNED to wear out every few years. (Wonderful American Planned Obsolescence)

A modern Passive Solar Energy Powered Absorption Chiller can cool a building and make ice when the sun is shining, and then use the ice to cool the building, when the sun is not shining.

Using Ambient EarthTemperature is another technique that can be used to reduce (or eliminate) summer cooling bills AND winter heating bills. Deep caves remain the exact same temperature year round, regardless of surface air temperature variations. The enormous thermal mass of the Earth maintains a constant “weighted average” temperature every day of the year. Ambient Earth Temperature is generally lower, the farther you are from the equator, but for most of the continental U.S. it is mid 50’s to high 60’s F.

A large-diameter (22 inch), one-hundred-foot-long, Passive Solar Energy Ground Tube can be buried 6-or-8 feet deep. It needs to be packed with conductive moist dirt. Natural convection can draw air through such as tube, for use in a Zero Energy Design Thermal Buffer Zone (not the interior of the house). In the winter, it will warm outside replacement air. In the summer, condensation will form on the walls of the tube, as it both cools AND dehumidifies Thermal Buffer Zone replacement air. A condensation drain is extremely important. NO staNDING WATER CAN BE ALLOWED IN THE TUBE. The passive cooling ground tube concept is only cost-effective in the summer in non-tropical areas, where the ambient temperature of the Earth is below 70 degrees F. (It is 72 degrees in Orlando Florida, where ground tube air cooling is less than marginally effective.)

Ambient Temperature Earth can be used cost-effectively in most of America (and elsewhere) in ActiveGeothermal Well Heat Pump Systems. A water well is drilled about 250 feet deep that can recirculate water at 6-to-10 gallons per minute. The ambient-Earth-Temperature well water is fed into a water-jacketed heat pump. Water is 25 times more thermally conductive than air. Well water is cooler than peak summer air, and warmer than the lowest winter air temperature. The net effect is a heating-and-cooling system with a much higher SEASONAL ENERGY EFFICIENCY RATIO (SEER), and therefore much lower energy costs. (But this is not considered a Passive Solar Energy Technology.)

Ambient Earth Temperature Water can also merely be pumped directly through a radiator to cool and dehumidify replacement air going into the base of the Solarium Thermal Buffer Zone (not the interior). This approach would NOT require the water-jacketed heat pump installation-or-operating expense. If the water pump and circulating fan on such a system are powered by a photovoltaic system, this would be a FREE, CLEAN-ENERGY Solar Cooling and Dehumidification System. The interior of the house would “think” it was built is a cool climatic zone in the summer, and it would be very easy to keep cool, with minimal energy consumption.

Please browse our ZeroEnergyDesign.com technology website. Take a look at the Table of Contents and 80-page Preface to our eBook.

We hope we can help you experience Abundant Energy In Harmony With Nature(R)